| 摘要 |
PURPOSE:To purify exhaust gas and improve the engine performance by providing the second exhaust passage communicated to the first exhaust passage and the underwater, and arranging a catalyst on the second exhaust passage at a position above the water surface when a ship is stopped. CONSTITUTION:The exhaust pipe 28 of the first exhaust passage 25 guides exhaust gas to an exhaust expansion chamber 24, and the exhaust gas is purified by a catalyst 31 at this time. The passage cross section area at the downstream side is made larger than that at the upstream side of the exhaust pipe 28, the exhaust resistance of the exhaust gas is reduced, and the engine performance can be sufficiently secured by utilizing the exhaust pulsation effect. The exhaust gas is guided to the second exhaust passage 26 and discharged into the water from a main exhaust discharge port 33, and a lattice-shaped catalyst 34 is arranged at a position above the sea water surface level L when a ship is stopped to purify the exhaust gas. The second exhaust passage 26 is not squeezed at the position of the catalyst 34, the flow resistance of the exhaust gas is reduced, and the reduction of the engine performance is prevented. An auxiliary exhaust passage 38 is branched from the catalyst downstream section of the second exhaust passage 26, and the exhaust gas at a low speed can be purified. |
